Shell script to embed a landscape video inside a blurred, portrait version of itself.

landscape_to_blurred_portrait.sh

#!/bin/bash

if [ -z "$1" ]; then
  echo "Usage: $0 <input_video>"
  exit 1
fi

input_file="$1"

if [ -z "$2" ]; then
  output_file="final_output.mp4"
else
  output_file="$2"
fi

VIDEO_WIDTH=1080
VIDEO_HEIGHT=1920
BLUR_SIGMA=20
blurred_bg="background.mp4"

# Chat-GPT (4o) helped get started with these:
# Step 1: Create the blurred, zoomed, and cropped background video
ffmpeg -i "$input_file" -vf "scale=${VIDEO_WIDTH}:${VIDEO_HEIGHT}:force_original_aspect_ratio=increase,crop=${VIDEO_WIDTH}:${VIDEO_HEIGHT},gblur=sigma=${BLUR_SIGMA}" -c:a copy "$blurred_bg"

# Step 2: Resize the original video and overlay it onto the blurred background
ffmpeg -i "$blurred_bg" -i "$input_file" -filter_complex "[1:v]scale=${VIDEO_WIDTH}:-1,format=rgba,colorchannelmixer=aa=1.0[fg];[0:v][fg]overlay=0:(main_h-overlay_h)/2" -c:a copy "$output_file"

rm "$blurred_bg"

echo "Output saved as $output_file"